Answer
6,122 hm
Explanation
You can carry out operations on the like terms only. So convert all units to one unit.
I will convert them to dam
1 km =100 dam
73 km = 73 × 100
=7,300 dam
11 km = 11× 100
1100 dam
1 hm = 10 dam
47 hm = 47 × 10
= 470 dam
55 hm = 55× 10
= 550 dam
73km 47hm 2dam - 11km 55hm = (7300+ 470+2) - (1100+550)
= 7,772 - 1,650
= 6,122 hm
